API: Measure a single function

[nedbat]

Originally reported by space one (Bitbucket: spaceone, GitHub: spaceone)

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It would be nice if the docs contain a single code snipped for how to measure a single function. Might this be possible?

from coverage import Coverage
def my_target_function():
   return True
cov = Coverage()
cov.measure(my_target_function)
my_target_function()
cov.stop()
cov.report()

measure should be able to handle functions/classes/modules. I'm okay to give as second parameter the source-code-file (but I guess the function internally has a reference to it anywhere). (I think the source-code file is also only needed for the HTML report?!).

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• Bitbucket: https://bitbucket.org/ned/coveragepy/issue/531

[nedbat]

Original comment by Loic Dachary (Bitbucket: dachary, GitHub: dachary)

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Could you please explain why the proposed measure() function is better than doing the following (which is what the documentation proposes):

#!python
from coverage import Coverage
def my_target_function():
   return True
cov = Coverage()
cov.start()
my_target_function()
cov.stop()
cov.report()

When running the above you get:

Name        Stmts   Miss  Cover
-------------------------------
sample.py       8      7    12%

[nedbat]

Original comment by space one (Bitbucket: spaceone, GitHub: spaceone)

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Because I want to use this in unit tests. I want to use this in combination with https://bitbucket.org/ned/coveragepy/issues/503/get-coverage-as-percentage.
With the example you posted I would need to

1. specify a source file in some configuration file for each unit test
2. I cannot use the default plaintext output (which you posted) as this doesn't show single functions but only files
3. i would then need to either parse the HTML output OR write an own reporting class (and watch out for API changes at every new release)

[nedbat]

Original comment by Loic Dachary (Bitbucket: dachary, GitHub: dachary)

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@spaceone thanks for clarifing the relationship between these two issues. I would not know how to implement that but at least I now understand what it is about ;-)